| 摘要 |
PURPOSE:To provide a thermal recording material enhanced in water resistance, plasticizer resistance and oil resistance and having favorable long-time preservability, by providing a protective layer comprising an emulsion of polyvinyl acetate on a thermal color forming layer. CONSTITUTION:A normally colorless or light-colored color forming dye used in the thermal color forming layer may be a leuco dye based on fluoran, triphenylmethane, spiropyran, Auramine, Rhodamine lactam, phenothiazine or the like. A color developing substance for developing the color of the dye when being heated is preferably a phenolic compound with low solubility in water, particularly, one having at least two hydroxyl groups in a molecule thereof. A binder used in the color forming layer may be any of those known. In providing the protective layer, an emulsion of polyvinyl acetate is used as a protective layer forming agent together with a hardener, a pigment and a lubricant or the like. If required, a water-soluble high molecular weight substance may be jointly used, whereby favorable results can be obtained. |
